1. Technical Field
The present invention relates to a method and apparatus for sending and receiving and for encoding and decoding a telop image. More particularly, this invention relates to such a method and apparatus for transmitting information representing a telop image over a network and to an encoding and decoding method and apparatus for implementing the same.
2. Background Art
Conventionally, the SDI (Serial Digital Interface) standard (e.g., SMPTE 259M) has been employed as an interface for transmitting the video and sound signals for use with the services in the broadcasting station. In this standard, the information representing a telop image includes an OA fill signal indicating color information for a synthesis image and an OA key signal including transparency information indicating a transparency with which an image to be synthesized is displayed through the synthesis image. Conventionally, color information and transparency information are transmitted via independent signal lines, and synthesized synchronously in a unit of frame with a Genlock (Generator lock) signal, for example.
Since no prior art document has been found, description regarding the prior art documents is omitted.
The prior art apparatus, however, is not able to display a telop image appropriately if color information and transparency information in the telop image are transmitted over a transmission path where the amount of delay fluctuates, such as a packet transfer network, for example.